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profile: Another profiling musttail call fix [PR119535]

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As the following testcase shows, EDGE_FAKE edges from musttail calls to
EXIT aren't the only edges we should ignore, we need to ignore also
edges created by the splitting of blocks for the EDGE_FAKE creation that
point from the musttail calls to the fallthrough block, which typically does
the return or with PHIs for the return value.

2025-04-01  Jakub Jelinek  <jakub@redhat.com>

	PR gcov-profile/119535
	* profile.cc (branch_prob): Ignore any edges from bbs ending with
	musttail call, rather than only EDGE_FAKE edges from those to EXIT.

	* c-c++-common/pr119535.c: New test.
This commit is contained in:
Jakub Jelinek 2025-04-01 11:45:16 +02:00 • committed by Jakub Jelinek
parent 02409a1459
commit b8de770442
2 changed files with 33 additions and 3 deletions
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5
gcc/profile.cc
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@ -1340,9 +1340,8 @@ branch_prob (bool thunk)
EDGE_INFO (e)->ignore = 1;
ignored_edges++;
}
/* Ignore fake edges after musttail calls. */
if ((e->flags & EDGE_FAKE)
&& e->dest == EXIT_BLOCK_PTR_FOR_FN (cfun))
/* Ignore edges after musttail calls. */
if (e->src != ENTRY_BLOCK_PTR_FOR_FN (cfun))
{
gimple_stmt_iterator gsi = gsi_last_bb (e->src);
gimple *stmt = gsi_stmt (gsi);

31
gcc/testsuite/c-c++-common/pr119535.c Normal file
View file

@ -0,0 +1,31 @@
/* PR gcov-profile/119535
/* { dg-do compile { target musttail } } */
/* { dg-options "-fprofile-generate -O2" } */
/* { dg-require-profiling "-fprofile-generate" } */
[[gnu::noipa]] int
foo (int x)
{
return 42 + x;
}
int
bar (int x)
{
foo (x);
foo (2);
[[clang::musttail]] return foo (3);
}
int
baz (int x)
{
if (x == 42)
return -1;
else if (x == 15)
return 25;
else if (x == 26)
[[clang::musttail]] return foo (4);
else
[[clang::musttail]] return foo (5);
}